Apparatus for sharpening pencil refills



y 8, 1951 H. BUSER 2,552,402

APPARATUS FOR SHARPENING PENCIL REFILLS Filed March 18, 1947 FIG. I FIG.2

"Inventor:

HANS 'BUSER,

Attorneys:

Patented May 8, 1951 REFILLS Hans Buser, Zurich, Switzerland IApplication March 18, 1947, Serial No. 735,317 In Switzerland December.29, 1944 Section 1, Public Law 690, August 8, 1946 Patent expiresDecember 29, 1964 Claims.

The present invention relates to an apparatus ,for sharpening pencilrefills having means proof contact in different directions or in thesamedirection but at different speeds.

Further features of the invention will be apparent from the followingdescription and the drawing setting forth preferred embodiments'of theinvention.

In the-drawings: Y

Figure 1 is a cross-sectional view of one embodiment of the invention;

Figure 2 is a longitudinal section of the embodiment of Figure 1; I

Figure 3 is a cross-sectional view on the line wa of Figure 4;

Figure 4 is a, horizontal sectional view of a second constructionalembodiment;

Figure 5 is a horizontal sectional view on the line 22-12 of Figure 1,and

Figure 6 illustrates a detail.

In the case of the first constructional embodiment shown in Figures 1and 2, the pencil-refill rests for sharpening purposes only due to theweight of the refill-holder 5, on the friction-surface of a slantingfile I, which is attached by means of two connecting pieces 2 to a slide7. The slide 1 can be moved to and fro in the longitudinal direction inthe casing a (Figure 1) and in the course of this movement carries thefile with it. The slide 1 serves as driving means. On the slide 7 thereis fastened a rack 3 which engages in a pinion 4 which is rigidlyattached to a sleeve 4a. This sleeve 4a is arranged in vertical orapproximately vertical position in a holder on the casing 8 and isrotatably mounted therein. The refill-holder 5 of a pencil-refill can beinserted in the sleeve 4a until the tip of the refill rests against thefile l. The refill-holder 5 is secured against twisting in the sleeve 4aby means of a sexagonal holder having three set screws l3 arrangedradially in the sleeve (Figures 1 and 5), which are distributed at evendistances over the periphery thereof. These screws I 3 are set in such away that the refill-holder can slip down the sleeve by virtue of its ownweight until the tip of the refill rests against the file I. In thepinion 4 of the sleeve 4a there is a hole which 2 serves to limit thedepth to which the refill-holder can fall and thus prevents any damagingof the latter.

As the refill-holder may vary considerably in size, which fact may causedifficulty for an exact centering of the pencil-refill inasmuch as thelatter can easily break off, a centered bore is provided as clearlyshown in Figure 6 in the lower part, i. e. in the pinion part of thesleeve 4a, which bore corresponds to the diameter of the refill. Thisserves to center the refill and at the same time limit the depth towhich-the refillholder 5 can fall.

.Due to the arrangement of the friction surface I on the opposite sideof the refill from the point of pinion engagement with the rack 3, thesetwo parts will move in opposite directions atthe common point ofcontactof the tip of the refill and the friction surface 1, whereby aneffective sharpening of the refill is achieved.

The casingv 8 is completely closed and under the refill point acontainer can be provided to hold the graphite dust. This container(which is not shown in the drawing) can be slipped in and out of thecasing for emptying the graphite dust.

The mode of operation is apparent from Figures 1 and 2. Therefill-holder together with the refill is inserted from above into thesleeve 4a and lowered until the tip of the refill rests against thefriction member. The slide 1 is moved back and forth once or twice,which will effect sharpening of the refill. The refill-holder is thentaken out of the sleeve 4a together with the sharpened refill.

In the case of the embodiment as in Figures 3 and 4, the friction memberconsists of a disc 9 in the form of a truncated cone, the jacket ofwhich is designed as a friction surface and against which the tip of therefill of the refillholder inserted into the sleeve 4a rests. The axisof the friction disc 9 is connected via a pinion 9a to a gear wheel I2on whose axis a pinion I 2a is mounted which meshes with the toothedsector lea of a pivoted lever I!) having a spring H connected thereto.On operating thumb lever It), the friction disc 9 is turned and, via thepinion and the sleeve do, also the refillholder 5 and the refill. Aftereach movement the thumb lever 19 is returned to its initial position bythe tension spring H. Due to the arrangement of an intermediate gearwheel I? the sleeve 4a with the refill-holder 5 and the refill on theone hand, and the friction disc 9 on the other hand, are driven inopposite directions, so that with one or two operations of the thumblever H] a sharp refill-tip is obtained.

I claim:

1. Apparatus for sharpening pencil-refills comprising a casing, asubstantially vertical hollow sleeve in said casing, said sleeveconstituting a holder for a pencil refill, said refill-holder beingloosely inserted in said sleeve and a small inter.- mediate space beingformed between said refillholder and said sleeve, a screw inserted in aside of said sleeve and passing therethrough, said screw looselycoacting with said refill-holder to prevent relative rotation betweensaid sleeve and said refill-holder and allow free longitudinal movementof said refill-holder, said sleeve being rotatable, a pinion on thelower end of said sleeve, a slidable rack member in contact with saidpinion, drive means for said rack, a friction member comprising a filerigidly connected with said rack for movement therewith, said rack andsaid friction member being on different sides of the axis of saidrefill-holder, said refill resting against said file by virtue of itsown weight, said file sharpening said refill on movement thereof.

2. Apparatus as claimed in claim 1, characterized in that the rack is soarranged that the file and the refill move at the common point ofcontact in difierent directions.

3. Apparatus as claimed in claim 1, characterized in that the drivingmeans consists of a slide which can be moved to and fro in the casing.

4. Apparatus as claimed in claim 1, characterized in that said sleeveserving to hold the refill-holder has at the lower end thereof in thecentral axis a centered bore, said bore being dimensioned in accordancewith the diameter of the pencil-refill, so that said refill is guided bysaid bore and can be moved in said bore both in rotatory andlongitudinal directions.

5. Apparatus for sharpening pencil-refills comprising a casing, asubstantially vertical hollow sleeve rotatably journalled in the top ofsaid casing and extending into said casing, said sleeve constituting apencil refill-holder, said refill-holder being loosely inserted in saidsleeve and a small intermediate space being formed between saidrefill-holder and said sleeve, a screw inserted in a side of said sleeveand passing therethrough, said screw loosely coacting with saidrefill-holder to prevent relative rotation between said sleeve and saidrefill-holder and allow free longitudinal movement of saidrefill-holder, a pinion gear fixed adjacent the lower end of saidsleeve, a slide member movably mounted in said casing at substantiallyright angles to said sleeve, a rack connected to said slide in contactwith said pinion gear, a friction member comprising a file attached tosaid slide and arranged in proximity to the lower end of said sleeve andat an angle thereto, said rack and said friction member being ondifferent sides of the axis of said refill-holder, said refill insertedin said sleeve resting against said friction member under the force ofWeight of said refill, said slide upon moving rotating said refill incontact with said file thereby sharpening said refill.

HANS BUSER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 211,911 Johnston Feb. 4, 1879836,094 Cook Nov. 20, 1906 998,044 Spengler July 18, 1911 1,770,062Blomgren July 8, 1930 FOREIGN PATENTS Number Country Date 91,352Switzerland Dec. 1, 1921 388,588 Germany Jan. 15, 1924 151,706Switzerland Dec. 31, 1931 298,244 Italy July 2, 1932 183,672 SwitzerlandApr. 30, 1936

